Pedal board



V. J. MOHLER PEDAL BOARD Filed May 17, 1959 4 Sheets-Sheet l v. 1. MOHLER 2,187,911

PEDAL BOARD Filed May 1'7, 1959 4 Sheets-Sheet 2 Jan, 23, 1940. V, J. MOHLER PEDAL' BOARD Filed May 17, 19159 4 Sheets-Sheet 3 Jan. 23, 1940. v J, MQHLER 2,187,911

PEDAL BOARD Filed May 17, 195s 4 sheets-sheet 4 Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE PEDAL BOARD Application May 17, 1939, Serial N0. 274,091

17 Claims.

This invention relates to musical instruments and particularly, but not necessarily to electrical musical instruments employing alternating current sources, each of the tone frequency of some 5 particular partial tone and adapted to be selectively connected in an electrical network to effect conduction to an electrical sound producer of a waveform of voltage corresponding to a given quality of tone.

Instruments of the type above referred to employ one or more manuals and a pedal board mechanism by means of which alternating currents from diiierent alternating current sources can be impressed upon said electrical network by the action of electric switches which are controlled by the playing keys of said manuals and by pedals of said pedal board mechanism.

Each key or pedal, as the case may be, controls actuation of an electric switch of the form disclosed in my copending application Ser. No. 274,371 the form of which is such that each switch may connect with one or more alternating current sources and with an amplifier according as stops are set for predetermined timbres.

Certain of the more important objects of my invention are as follows:

To provide means for facilitating connecting a pedal board mechanism with and removal of same from the case of a console.

To provide means for automatically correlating electric switches in the console case with pedal controlled actuators when connecting the pedal board with the case.

To pro-vide means for preventing any possible injury to the electric switches when connecting the pedal board with the console case.

To provide means whereby during the operation of manually attaching the pedal board to the console case, a relation of one operating part to another will be definitely secured and the pedal board latched to the case so as to have a rigid connection therewith, yet be readily separable therefrom as and when desired.

To provide yieldable means upon a depressible pedal or selector for controlling operation of an electric switch in a manner whereby normal tension of said means functions to maintain a starting position of the means relative to a lever of said switch, the tension of the spring gradually increasing in proportion to the amount of pressure imposed upon said pedal or selector as the latter is being depressed, thereby imparting a circuit closing motion to said lever, and whereby any excess of pressure imposed upon the pedal or selector after the lever is in a closed circuit position will not be imparted to said lever.

To provide yieldable means actuable by a depressible selector for controlling a switch lever in a manner to insure against casual destruction of an intended and necessary relation of said means to said lever regardless of the amount of pressure imposed upon said selector.

The invention will be more fully understood by reference to the following description read in conjunction with the accompanying drawings, in which:

Figure 1 isy a diagrammatic illustration of a portion of an electrical network in which one of my multiple contact switches is interposed and adapted to be actuated by a foot pedal;

Figure 2 is a view partly in plan and partly in section of my improved pedal board showing same connected with the case of a console:

Figure 3 is a view in end elevation of the pedal board connected with the console case;

Figure 4 is a transverse section through portions of the console case and 'the pedal board;

Figure 5 is a section taken substantially on the line 5 5 of Figure 4;

Figure 6 is a transverse section taken substantially on the lineV 6 6 of Figure 2;

Figure 7 is a detail section taken on the line 1 7 of Figure 6; of Figure 2;

Figure 8 is a detail section taken on the line -8 of Figure 6, and,

Figure 9 is a schematic illustration of a foot pedal-controlled switch actuator showing the normal position thereof in full lines and a depressed position of same in dotted lines.

In carrying my invention into practice, I do not confine myself to the use of any particular type of musical instrument or the type of mechanism to be actuated by the pedals of my improved pedal board mechanism. However, the invention is primarily designed, adapted and intended for use in connection with electrical musical instruments in which alternating currents at different tone frequencies are used with which to simulate the different tones of a pipe organ upon conversion of said currents into audible sound. Reference made herein to alternators for originating alternating currents shall therefore be construed to mean any well known alternating current sources from which currentsat different tone frequencies can be conducted to a suitable amplifier, thence converted into audible sound.

In electrical musical instruments employing plural contact switches, each switch controls an electrical network through which the developed cuit making and breaking contact devices for controlling conduction of alternating currents through said network.

In the schematic illustration, Figure 1 of the accompanying drawings, I show av portion of an j electrical network for selective conduction ofalternating currents to an amplifier from a plurality of alternating current sources, each productive of alternating current of some particular tone frequency, such for example, a fundamental tone frequency and a Ynumber of frequencies which are harmonically related to said fundamental frequency.

The electrode of each condenser 23 is connected by a lead wire 25 to a common wire 255, connected to one side of a polarizing source 26. A multiple contact switch 29 has individual contact springs 2 each connected to an electrode 22 of an Aindividual condenser'and provided with a series resistor 229.

Each of said springs 2| has normal open circuit engagement with a contact device 21, connected in the circuit as shown and to ground 28 by a conductor 29. A device 30 is yieldingly urged by a springy 3| to a position to maintain normal engagement of the springs 2| with their respective grounded contact devices 21, and as shown, said device has engagement at 32 with a depressible selector 33,`such as a playing key, foot pedal or the like, normally held elevated by a spring 34'.

For each spring 2| is a contact device 34, one of which is electrically connected with a current conductor 35, another with a similar conductor 36 and the other with a like conductor 31, each having a contact device 38, adapted to make closed circuit connectionwith a coacting contact spring 39 of a tappet mechanism 40. c

The tappet contact springs 39 are tapped to a voltage divider 4| through circuit leads 42, provided with series resistances 44, thel said voltage divider having terminals and 46, adapted to be coupled to the input circuit of an amplifier, not shown.

Electrically connected to the respective conductors 35, 36 and 31 and to ground 28 through resistors 41, are bus-bars 48, 49 and 50.

In practice, there of course will be one condenser 22 for each fundamental tone intended to be produced. As many tappets 40 may be employed as desired, depending upon the number of different qualities of tone which the instrument is capable of producing. The number of conductors 48, 49 and 59 .employed will depend upon the number of' contact devices per selector 33. rIhe tappets function in a manner common in the art and it will suffice to say that according as one or another thereof is rendered active in the network, alternating currents will be fed to the distributors 48, 49 and 50 from such of the alternating current sources 22 as are in closed circuit in the network upon the depression of a selector. Each key switch, will, however, be connected with an alternating current source for impressing alternating current upon the network which will correspond to the fundamental tone frequency denoted by the keys position in the musical gamut.

5| denotes a portion of a console case and 52 a pedal board.

In the lower front portion of the console case is a switch housing 53, secured at 54 to the lower wall 55 of the case. Said housing is provided with a vertical front wall 56 having equi-distantly spacedl apart vertical slots 51, through each of which extends a vertically tiltable control lever 58 of a multiple contact switch 59, the latter being functionally similar to the multiple contact switch 20 disclosed in Figure 1 of the drawings, whereby, when the lever 58 is moved vto a closed circuit position against the normal action of a spring 588, different alternating current sources will eifect conduction of alternating currents at different tone frequencies to such tappet of the instrument as has been depressed for the production of a predetermined quality of tone.

The control lever 5B of each of the aforel mentioned switches 59 has riveted or otherwise suitably secured thereto, a metal clip 6|, provided with a flat surface 62. The slots 51 in the front wall of said housing"53 are disposed in Aa horizontal series and upon reference particularly to Figure 9 of the drawings, it is noted that these slots are disposed directly in back of a rectilinear bar 622 of rigid material such as a continuous steel strip. It is also noted in this figure that in the open circuit positions of the switch levers 58, the flat surface of each clip 6| is disposed slightly below the plane of the upper edge of said bar 622.

The pedal board 52 comprises a frame 63 having arearwardly disposed foot rest or rail 64 and a plurality of pedals 65 of which there is one for each of the switches 59. Said pedals are each pivoted in the frame for vertical motion against the normal tendency of a leaf spring 66, the free end of which has frictional engagement with a felt faced cross bar 61. The forward ends of the pedals have reduced portions 68'intowhich are securely driven pins 69, the grain of each l of which runs crosswise of the grain of portion v68 in which it is tted. These portions 68 of the respective pedals have tapered front faces 10, in front of which is the vertical branch 1| of a leaf spring 12. Each of these springs has a branch 13 secured at 14 to the forward lower face of the pedal. The portion of the spring in front of the tapered front end of the pedal receives a screw 15 which is driven into the portion 68 of the pedal and into the pin 69, whereby the vertical branch of the spring can be adjusted laterally and be capable of flexing relative to the tapered face of said portion 69. g

The front of the pedal board frame includes a vertical rail 16, side rails 11, a top rail 18 and a bottom `cross bar 19. The reduced portion 68 of each pedal extends through a vertical slot 89 in the rail 16, and as shown, each slot is provided with upper and lower felt buffers 8|and 82 to cushion the vertical motion of the pedal.'

Secured at 83 to the side rails 11 of the pedal frame are forwardly projecting metallic latch members 84 provided with reduced shanks 85 which terminate in lugs 86. The lug of each shank is beveled at 81 and rearwardly thereof the shank 85 is formed with a recess 88. The pedal board has two such latch members, one at each end thereof, and as shown in Figure 6,

the Shanks 85 are adapted to be extended through slots 89 in the front wall of the console case player.

and into the case and through the bifurcations 90 in keepers 9| which project forwardly from the switch housing 53 and are disposed directly in back of said slots 89, the side walls of the bifurcations being flared downwardly toward the medial centers of the keepers.

Upon reference to Figures 4 and 6 of the drawings, it is noted that the vertical branches H of the springs 'l2 are curved upwardly and forwardly and are proportioned so that their free ends project a considerable distance in front of the frame of the pedal board and are thereby adapted to be extended through receiving slots 92 in the front wall of the console case and into the case just suiiiciently to enable said ends to be disposed above the flat faces 62 of the clips on switch levers 58 and in back of the bar 622 when the pedal board is attached to said console case. In Figure 9 wherein one of said springs is illustratedon an enlarged scale, it is noted that the free end of the spring is upset to provide a depending V-shaped lug, presenting a forwardly disposed cam surface 92 and a curved lower portion 93, the latter normally disposed substantially medially of the vertical center of the clip and merely lightly resting on the flat face thereof and with no pressure thereagainst. When 'the pedal is depressed against the normal urging tendency of its spring 65, the forward extremity of the pedal spring 12 descends from a position spaced above the upper edge of the bar 622 to a position which gradually approaches said edge. During this movement of' the pedal, the spring 'i2 flexed and yieldingly stressed or tensioned in an amount proportional to the amount of pressure imposed upon the pedal by the foot of the In sc doing, the switch lever is rocked to a closed circuit position, the curved lower portion 93 of the spring moves rearwardly or toward the inner face of the bar 622. The angu- =lar stop portion 94 abuts said bar 622 as shown in dotted lines in Figure 9, at which time, the spring rests directly upon the upper edge cf the bar so that regardless of the amount of further pressure imposed upon the foot pedal, no additional pressure will be transferred to the switch lever 58. In consequence of these niceties in the construction of these parts, and the precision with which they function. it follows that not only is it possible to prevent an excess of pressure being applied to the switch lever, but

that in addition thereto, the effective actuating portion of said spring 'i2 will be held against any possible disasscciation from the clip El, the moment the stop 94 contacts said bar 622.

By reason of the manner in which the springs 'l2 are attached to the pedals 65, it manifestly follows that said springs can be adjusted initially to positions enabling their free ends to eX- tend approximately the same distance from in front of the pedal board frame. The spacing apart of the pedals longitudinally from each other is calculated with regard for a like spacing of the switches 59 from each other,

" whereby when connecting the pedal board with the console case, said springs will be properly coordinated with the controlling levers 58 of .said switches.

In attaching the pedal board to the console case, the same is lifted manually and moved forwardly to cause the shanks of the metallic latch members to pass into the bifurcations 93 in the keepers 9 I, simultaneously therewith causing the free ends of the pedal springs I2 te extend through their respective slots 92 in the front wallr of the console case. In so doing, the flared front ends of said pedal springs are cammed` over the upper edge of bar 522 so as to drop behind said bar and thereby correlate their portions 92 with the lfiat faces 62 of the clips 6i of the switch levers 58. By reason of the flared side walls of the bifurcations 90 in the keepers 9i, the Shanks of the latch members gravitate readily into correct positions to insure engagement of the keepers in the recesses 88 in said Shanks. This definitely centers all of the free ends of the foot pedal springs 'l2 relative to the coacting switch levers 58.

To the best of my knowledge, it is broadly new in the art to provide in combination with the circuit controlling lever of an electric switch, a spring actuable 'oy a depressible selector or the like and functioning to prevent an excess of pressure imposed upon said selector being transferred to said lever after the latter is moved to a circuit making position. Were it not for this novel feature of my invention, obviously any continued pressure of the foot of the player upon ay pedal after the switch lever has been moved to circuit making position, would result in disrupting the ccacting working parts of the mechanism, rendering same wholly inoperative.

It is likewise true to the best of my knowledge new in the art to provide in combination with a console case having electric switches or other` selector controlled devices, a pedal board adapted during attachment thereof to the case, automatically to effect a coacting relation 0f the selectors with their controlling devices and simultaneously therewith latch the pedal board to the case.

It is also new in the art to provide an organization of switches, each actuable by resilient means on a depressible selector and adapted automatically to compensate itself to varying degrees of pressure imposed upon the selector and to be held against disassociation from` the switch lever after the latter is moved to a circuit closing position.

The term selector employed herein shall be construed to include playing key or other device, the actuation of which is intended to control operation of an electric switch.

What I claim as my invention is:

1. In mechanism of the class described, a console case having an electric switch provided with a vertically movable circuit controlling member; means for yieldingly urging said member in an open circuit direction; a pedal provided with a leaf spring having an end related to the controlling member to press thereagainst and move the member in a circuit closing direction against the action of said urging means when depressing said pedal; and Ymeans for preventing an excess of spring pressure upon said circuit controlling member when the latter is moved to a circuit closing position upon depressing said pedal.

2. In mechanism of the class described, a console case having an electric switch provided with a vertically movable circuit controlling member; means for yieldingly urging said member in an open circuit direction; a pedal having a leaf spring, one end ci which is related to the controlling member to press thereon and move same to .a circuit closing position when depressing said pedal; and means disposed under said end` of the spring for arresting further pressure of the spring against said controlling member when the latter arrives at a circuit closing position and during 'continued application of downward pressure of the foot against said pedal.

3. In mechanism of the class described, a console case having a set ofy electric switches, each switch having a forwardly disposed, vertically movable circuit controlling member; a pedal board detachable from the console case; a leaf spring on each pedal of said pedal board and provided with an end related to the circuit controlling member of a respective switch to exert pressure thereagainst and thereby move same in a circuit closing direction when depressing the pedal; and means common to the springs of all pedals of said pedal board for arresting further pressure of any spring against a respective circuit controlling member when thev latter reaches a close circuit position.

4. In mechanism of the class described, a console case having a longitudinal row of electric switches, each switch having a forwardly disposed, vertically movable, circuit controlling member; means for yieldingly urging each circuit controlling member to an open circuit position; and means for individually actuating said circuit controlling members and including a set of pedals, each having a leaf spring individual to one of said switches and engageable with the circuit controlling member thereof to impose yielding pressure thereagainst and move same to a circuit closingk position upon depressing said pedal.

5. In mechanism of the class described, a console case having a longitudinal row of electric switches, each switch having a forwardly disposed, vertically movable, circuit controlling member; means for yieldingly urging each circuit controlling member to an open circuit position; means detachable from the console case for individually actuating said circuit controlling members and including pedals, each having a leaf spring individual to a single one of the switches and engageable with the circuit controlling member thereof to impose yielding pressure thereagainst and move same to a circuit closing position upon depressing said pedal; and means for simultaneously correlating the springs with their respective circuit controlling members when attaching the detachable means to said console case.

6. In mechanism of the class described, a pedal having a forwardly bowed leaf spring secured at one end thereto; a rigid bar underlying and spaced apart from the opposite end of the spring when the pedal is elevated and against which said opposite end of the spring is engageable when depressing the pedal, and an electric switch having a forwardly disposed circuit controlling member in back of said bar and against which the free terminal of said opposite end of the spring bears lightly when the pedal is elevated. i

7. In mechanism of the class described, a pedal having its back end tapered in a downward direction; a leaf spring secured at one end to the pedal and extending upwardly in back of said tapered end thereof and flexible relative thereto and provided with an upwardly and rearwardly bowed portion.; and an electric switch having a circuit controlling member freely engaged by the free extremity of said bowed portion of the spring so that upon depressing the pedal the spring yieldingly imposes pressure upon said controlling member to move same to a circuit closing position.

8. In mechanism of the class described, a pedal having its back end tapered in a downward direction; a leaf vspring secured at one end to the pedal and extendingy upwardly in back of said tapered end thereof and provided with an upwardly and rearwardly bowed portion; an electric switch having a circuit controlling member engaged by the free extremity of said bowed portion of the spring so that upon` depressing the key said extremity bears yieldingly against said controlling member to move same to a-circuit closing position; and means for limiting the amount of spring pressure against said controlling member when the latter reaches a circuit closing'position.

9. In mechanism of the class described, a console case; a pedal board detachable from said console case and having pedals, each of which has a leaf spring, one end of which is insertable in said console case when attaching the pedal board to the latter; a set of circuit controlling members located in said console case and each thereof associated with said one end of the spring of; a respective pedal so as to be actuated thereby when depressing the pedal; and means in front of said circuit controlling members constituting a baffle in the path of insertion of the aforementioned pedalsprings and for effecting an actue ating relation of said springs to said circuit controlling members,

10. In mechanism of the class described, a console case; a pedal board detachable from said console case and having pedals, each of which has a leaf spring, one end of Vwhich is insertable in said console case when attaching the pedal board to the latter; a set of circuit controlling members located in said console case and each thereof associated with said one end of the spring of a respective pedal so as to be actuated thereby when depressing the pedal; and means in front of said circuit controlling members providing a baille in the path of insertion ofthe aforementioned pedal springs and for effecting an actuating relation of the springs to said circuit controlling members and limiting the amount of pressure of the springs against said members when depressing said pedals.

11. In mechanism of the class described, a console case; a pedal board detachable from said console case and having pedals, each of which has a leaf spring, one end of which is insertable in said console case when attaching the pedal yboard to the latter; a set of circuit controlling members located in said console case and each thereof associated with said one end of the spring of a respective pedal so as to be actuated thereby when depressing the pedal; means in front of said circuit controlling members providing a baiile in the path of insertion of the aforementioned pedal springs and for effecting an actuating relation of the lsprings to said circuit controlling members and limiting the amount of pressure of the springs against said members when depressings aid pedals; and means for latching said pedal board tosaid console case.

l2. In a musical instrument employing electric switches, each actuable to control conduction through an electrical network of alternating voltage and including a circuit controlling member having a portion against which pressure can be applied to move said member from an open to a close circuited position in said network; pedals individual to respective switches; and a leaf spring on each pedal and having a free end lightly touching an aforementioned portion of the controlling lmember of a respective switch and removably associated therewith and serving when depressing said pedal freely to ride a surface of said portion while pressing thereagainst in a direction to move the circuit controlling member to a close circuit position. y

13. In mechanism of the class described, a console case; a switch housing in said console case and having a front wall provided with a longitudinal row of spaced apart vertical slots; electric switches contained in said housing and each havA ing a circuit controlling member with a portion thereof projecting through a respective vertical slot in the aforementioned front wall of said switch housing; and a pedal board havingcle- 'pressible pedals, each of which has a leaf spring extending` into the console case and disposed above the aforementioned projecting portion of the controlling member of a respective switch and serving yieldingly to press thereagainst and thereby move the controlling member in a circuit closing direction when depressing said pedal.

14. Mechanism of the class described comprising a console case; a pedal board; bifurcated keepers at the respective ends of said console case; and latch members at the respective ends of the pedal board, said latch members being insertable in said bifurcations of said keepers and having lugs engaged in back of the keepers for detachably securing the pedal board in xed relation to said console case.

15. In an electrical musical instrument, a set of depressilole selectors, said selectors being respectively assigned to different notes of the musical scale; a set of electric switches, each switch having a circuit controlling member in wiping engagement with a respective selector and serving when pressed upon by the selector to impart motion in a circuit closing direction to said controlling member.

16. In an electrical musical instrument, a set of depressible selectors, said selectors being respectively assigned to different notes of the musical scale; a set of electric switches, each switch having a circuit controlling member in wiping engagement with a respective selector and serving when pressed upon by the selector to impart motion in a circuit closing direction'to said controlling member; means by Which the set of selectors can be attached as a unit to or removed as a unit from a console case; and means by which the set of switches can be attached as a unit to or removed as a unit from said console case.

17. In an electrical musical instrument, a set of electric switches, each switch having a tiltable circuit controlling member; means individual to each circuit controlling member for urging same to a circuit closing position, each circuit controlling member having a portion provided with a smooth, at face; a depressible selector for each switch and provided with a leaf spring, one terminal of which is related to the at, smooth face of the circuit controlling member of the switch and serving to impose pressure thereagainst and move the circuit controlling member against the action of its urging means and to a circuit closing position; and means related to the aforementioned terminals of the springs of said selectors and engageable therewith for limiting the amount of spring pressure imposed upon any circuit controlling member.

VALENTINE J. MOHLER. 

